Changes

In some practices, such as [[bioretention]], [[swales]] or [[stormwater planters]], the flow limiting component is usually the [[filter media]]. In other, usually underground practices such as [[infiltration trenches]], [[infiltration chambers]], and [[exfiltration trenches]], the [[pipe]] will be the primary flow limiting component. See also [[flow control]].  

In some practices, such as [[bioretention]], [[swales]] or [[stormwater planters]], the flow limiting component is usually the [[filter media]]. In other, usually underground practices such as [[infiltration trenches]], [[infiltration chambers]], and [[exfiltration trenches]], the [[pipe]] will be the primary flow limiting component.  

 

See also [[flow control]] and [[underdrains]].  

Manufacturers of perforated pipe are often able to provide the open area per meter length. Where this information is not directly available, the open area can be calculated by measuring the perforations and summing the open area per meter. The maximum flow rate through a perforated pipe (''Q_{max, pipe}'', m³/s) may be calculated as:  

Manufacturers of perforated pipe are often able to provide the open area per meter length. Where this information is not directly available, the open area can be calculated by measuring the perforations and summing the open area per meter. The maximum flow rate through a perforated pipe (''Q_{max, pipe}'', m³/s) may be calculated as: